1. Department of Parasitology, and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 660-702, Korea.
2. Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, Seoul 110-799, Korea.
3. Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul 120-752, Korea.
4. Department of Parasitology, Chungbuk National University College of Medicine, Cheongju 361-711, Korea.
5. Korea Association of Health Promotion, Seoul 157-704, Korea.
6. National Institute of Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia.